In a railcar bogie, an axle box accommodating a bearing rotatably supporting a wheelset is supported by a bogie frame through an axle box suspension. For example, in PTL 1, a bogie frame includes a pair of side sills extending in a car longitudinal direction and a cross beam connecting the pair of side sills in a car width direction, and an axle box suspension (axle spring) connects an axle box and the side still of the bogie frame.
PTL 2 proposes a bogie including: a bogie frame from which side sills are omitted; and plate springs each of which is long in a car longitudinal direction. Longitudinal direction middle portions of the plate springs are supported by respective attaching portions provided at both respective car width direction end portions of the cross beam, and both longitudinal direction ends of each plate spring are inserted into respective spring receiving members formed at the axle boxes.
At the time of maintenance of the railcar, wheel load adjusting work is performed, i.e., wheel load balance among wheels is adjusted. For example, in the bogie of PTL 1, a spring constant of the axle spring is changed by inserting a liner between the axle box and the axle spring or pulling out the inserted liner, and with this, the wheel load balance is adjusted.